Compounds Related to Acridine. XIII. Reactions of 9-Vinyl- and 9-Ethynylacridine with <i>C</i>,<i>N</i>-Diarylnitrones

Abstract

Abstract The reaction of 9-vinylacridine (1) with C,N-diarylnitrones (3) in xylene under reflux afforded 5-(9-acridinyl)-2,3-diarylisoxazolidines (4) and/or 9-acridinyl styryl ketones (5). On heating isoxazolidines 4 were readily converted into the styryl ketones 5 with the elimination of anilines: this is a new type of thermal decomposition of isoxazolidine ring. However, thermal decomposition of 3-(9-acridinyl)-2,5-diarylisoxazolidines (9) which were prepared from N-(9-acridinylmethylene)aniline N-oxide (7) and styrene (8), did not observed. On the other hand, the reaction of 9-ethynylacridine (2) with nitrones 3 in ethanol under the influence of hydrochloric acid proceeded smoothly to give the reversed 4-(9-acridinyl)-4-isoxazolines (11), which on heating were converted into the corresponding 4-oxazolines 12.